1. Field of the Invention
The present invention relates generally to the packaging of film or sheet type materials which themselves are used to package goods. More particularly, the present invention relates to the packaging of tubular casings for food products, specifically flattened, non-shirred casings for the continuous packaging of emulsions such as, for example, processed cheeses and luncheon meats.
2. Background of the Technology
In the packaging of food emulsions, in particular meat emulsions, into sausage-like packages, it is desired by the industry to use continuous tubular casings in order to minimize the interruptions, i.e. downtime, to what can generally be classified as "automated food stuffing equipment." Generally, continuous flattened tubular casings are available packaged on, for example, a roll, a coil, a wheel or a spool, or, alternatively, packaged in an accordion-folded or pleated manner. A roll or spool, as well as a coil or wheel, of course, normally, although not always, needs to be mounted for rotation as the casing is fed into the automated stuffing machines. The accordion-folded pleated material, on the other hand, does not need to be removed from its package for use, but is simply fed from the opened shipping carton directly into the automated stuffing machinery.
Where non-shirred, flattened casing is to be used, one approach to increasing the amount of running time, between start-up of the automated packing equipment and shut-down to load in new casing material, is to increase the size of the roll, coil, spool or wheel (hereinafter collectively referred to as "rolls") on which the flattened casing is wound. This has limitations, in that the larger the size of the roll, the heavier it becomes and the more cumbersome it becomes to handle. As a consequence, heavier-duty feed equipment is required to mount such rolls, and relatively higher-powered drive equipment is required to overcome the greater static inertia of such packaging to feed out the casing material wound thereon. In addition, the mounting of enlarged rolls becomes more difficult, as such increased weight packaging is considerably less easily handled. Thus, the weight of the packages of flattened casing becomes a significant factor in relation to the facility of their use.
Another approach that has been proposed is related to the packaging of the flattened coils in the accordion-folded, pleated style (hereinafter referred to as "folded" or "folding") in boxes. Firstly, folding of the flattened casing enables complete filling of squared boxes. This is an improvement in terms of space economy in comparison to the packaging of cylindrically shaped rolls in squared boxes. However, weight of the package is still a factor. A variety of approaches have been proposed whereby the tail end of folded flattened casing in a given box (the last portion of the flattened casing remaining in the box as it is emptied) can be attached to the lead end of a casing extracted from a new and succeeding box. The most simple approach is to splice the two ends together, on-the-fly, with some form of adhesive, for example, tape. However, with the high-speed machinery that is used at present for automated packing, splicing on-the-fly requires a heightened degree of manual dexterity and not all are capable of doing it routinely on an error-free basis, very rapidly as is required.
Another approach is described in West German Laid Open Patent Application (Offenlegungsschrift) 33 18 373.2. In this patent application, arrangements are described in which the tail end of the flattened casing is left to extend out of the packaging carton so that it may be spliced to the lead end of the next package of flattened casing. This splicing can be affecting while the automated stuffing equipment is in full operation, during the period in which the initial packaging carton is being emptied. Thus the degree of dexterity is not required to do it so quickly on-the-fly, as there is no need to do it instantaneously; rather it can be done as the material from the carton is feeding into the automated stuffing equipment.
There is a basic problem, however, inherent in any splicing technique. That is, the splice, if it holds, ultimately will encompass the food emulsion which is packed into it. The area of the splice, even though it may be functionally acceptable, still creates an unsightly joint on the food product which customers and users tend to find somewhat objectionable. Also, as suggested, frequently the splicing does not hold, causing even more downtime. Therefore, another approach is to enhance the ease of loading each package of flattened film casing, unspliced, into the automated equipment, and thus, enable that time to be shortened. This approach does include the downtime for changing the casing at the end of each packaging carton. However, on the other hand, it does eliminate the objectionable splice and the specter of inordinate downtime due to failed splices.
To load the casing into an automated stuffing machine, firstly the flattened casing must be threaded through a system of guides which may include rollers. This guide/roller system feeds the casing through the machine to the actual point where the food emulsion is to be stuffed into it. At about the point where the actual food stuffing occurs, the flattened tubular casing must be opened up to form a tube, for example a cylindrical shape, which can be subsequently stuffed with food emulsion. Many of the casing materials, especially the synthetic plastic materials, tend to be relatively difficult to open up and form into a tubular shape. In addition, due to the fact that the casing materials are quite flexible, they tend to be somewhat difficult to thread into and through the guide/roller system of the automated food stuffing equipment.
The focus of the present invention is on enhancing the threadability of the flattened casing through the guide/roller system and also on enhancing the opening up and formation of a tubular shape from that flattened casing subsequent to threading. The present invention also focuses on facilitating rapid extraction of the lead end of flattened casing from new shipping cartons of that casing. One aspect of the present invention incorporates both means for threading and means for subsequently opening up and forming a tubular shape, all in regard to flattened casing. Further, the present invention includes means for rapidly and easily opening new cartons of flattened casing and extracting the lead end of the flattened casing from that carton.